如何在Swift中以特定的方式从字符串中提取数字

import Foundation

func extractNumbersFromString(inputString: String) -> [String] {
    do {
        let regex = try NSRegularExpression(pattern: "\\d+", options: [])
        let results = regex.matches(in: inputString, options: [], range: NSRange(location: 0, length: inputString.utf16.count))
        return results.map {
            String(inputString[Range($0.range, in: inputString)!])
        }
    } catch let error {
        print("Invalid regex: \(error.localizedDescription)")
        return []
    }
}

let inputString = "I have 123 apples and 456 oranges."
let numbers = extractNumbersFromString(inputString: inputString)
print(numbers)  // Output: ["123", "456"]

func extractNumbersFromString(inputString: String) -> [String] {
    var numbers: [String] = []
    var currentNumber: String = ""
    let decimalDigits = CharacterSet.decimalDigits
    
    for character in inputString {
        if decimalDigits.contains(character.unicodeScalars.first!) {
            currentNumber.append(character)
        } else if !currentNumber.isEmpty {
            numbers.append(currentNumber)
            currentNumber = ""
        }
    }
    
    if !currentNumber.isEmpty {
        numbers.append(currentNumber)
    }
    
    return numbers
}

let inputString = "I have 123 apples and 456 oranges."
let numbers = extractNumbersFromString(inputString: inputString)
print(numbers)  // Output: ["123", "456"]